I have posted answers to these questions before, so you SHOULD browse the forums before asking again, but I will be nice and answer again. The Wii does read DVD-r and +R, no real difference in which is better or worse. Get a disc with good dark ink, it will last longer through time. Yes, burned games WILL wear down your lense faster. This is because they are constantly correcting for errors that are made when burning... the disc is written while it is spinning, errors are natural. The faster the burn (e.g. 8x is faster than 4x) the more erros will come up. think of it this way... what is easier for you to read, a typed essay or an essay written by a 10 year old by hand. Same thing with the discs. burn slowly, it will preserve your Wii's lense because it has to compensate for less "sloppiness" Really, you probably won't be able to fry the lense... it takes a lot to do it, but taking precautions is always nice. It might be good to note that legit games that you would buy from the store will wear down the lense as well, they are just less "sloppy" because they are pressed, not burned.

Just a quick side note:
The lense will also deteriorate with time. Really, we don;t yet know how well they did their lenses in the wii. A good example would be the PS2, that thing constantly had issues with the lense... MANY MANY people who had not modified their consoles had disc read errors. I myself had a PS2 that wouldnt read the DVD based games (silver factory bottom), yet it would read CD based games (blue factory bottom), so I had to get a new lense. This shows that the lenses do deteriorate over time just due to age and even through ready factory bought games.